Today's Deep-Dive: DAViCal

In this episode of The Deep Dive, we explore how dependent our daily lives have become on digital calendars—and what it really means to rely on big tech platforms to manage something as essential as our time.

The focus is on DAViCal, an open-source calendar server that implements the CalDAV protocol. At its core, DAViCal acts as a self-hosted cloud for calendar data. Instead of locking users into proprietary ecosystems, it relies on open standards that ensure interoperability across a wide range of applications—including Mozilla Calendar, Evolution, Apple Calendar (iCal), and iOS.

The episode breaks down two key standards:

• CalDAV – the communication protocol (like a rulebook) that allows calendar apps to talk to a server.
• iCalendar – the standardized data format (like a note card) used to store events and tasks.

This combination guarantees compatibility and freedom from vendor lock-in.

A major theme of the discussion is digital sovereignty. DAViCal is licensed under the GPL (General Public License), meaning users are free to use, study, modify, and share the software. This ensures transparency, long-term sustainability, and full control over sensitive calendar data.

The episode also highlights enterprise-level features that make DAViCal comparable to Microsoft Exchange or Google Workspace:

• Granular delegation of access – allowing assistants or team members to manage schedules without sharing passwords.
• Free/busy scheduling – enabling automatic availability checks for efficient meeting planning.

From a technical standpoint, DAViCal requires:

• A PostgreSQL database (for robust, enterprise-grade data handling)
• A PHP-capable web server (to process requests and interact with the database)

The developers recommend running it on open-source operating systems like Linux or FreeBSD, noting that such infrastructure performs best in open environments.

Beyond the software itself, the episode emphasizes the strength of its community-driven model. Contributions go far beyond coding—documentation, translations, user support, and feature design are all essential. This reflects the broader philosophy behind the project: open collaboration over corporate control.

The episode concludes by zooming out to a bigger question: If you can reclaim control over your calendar through open standards like CalDAV, what about other parts of your digital life—such as contacts (CardDAV) or email?

Ultimately, DAViCal represents more than just a tool. It embodies a commitment to digital independence, interoperability, and long-term ownership of your own data.

• https://www.davical.org/